Point Probe¶
Introduction¶
Point probes are sampling locations placed inside the fluid domain which record the time-evolution of local flow properties at a specific point. A probe may remain fixed in space, follow the motion of the fluid as a tracer, or move along a prescribed trajectory.
During runtime, probe data can be referenced by global variables when the Data Source is set to probe, enabling use in control logic or event triggers. For post-processing, the recorded time history for each probe is written to an individual output text file. These files are particularly useful for temporal or path-based analysis, including lifeline tracking, spectral analysis, mixing characterization, or exposure-based metrics.
Property Grid¶
General¶
- Probe Option
This setting controls how the probe position evolves during the simulation.
- Fixed
The probe remains at its initial location for the duration of the run. This mode is appropriate for stationary instrumentation such as dissolved oxygen sensors, pH probes, or level indicators.
- Initial Location
m | This is the initial location of the probe. Fixed probes will not move from this location.
- Start Time
s | This is the time at which the probe will enter the system and start recording data.
- Fluid Tracer
The probe behaves as a massless tracer and moves according to the local fluid velocity field. This option is useful for representing entities that are carried by the flow, such as suspended cells or particles.
- Initial Location
m | This is the initial location of the probe. Fluid tracer probes will move from this location according to the fluid velocity.
- Start Time
s | This is the time at which the probe will enter the system and start recording data.
- Prescribed Motion
The probe follows a user-defined displacement controlled by a UDF. This mode is suitable for tracking equipment or interfaces with known motion, such as impeller blades, baffles, or free surfaces.
- Initial Location
m | Prescribed motion probes will be displaced relative to this initial location.
- Start Time
s | This is the time at which the probe will enter the system and start recording data.
- Displacement X UDF
m | This UDF defines the probe position as a function of time. This is a System UDF.
- Displacement Y UDF
m | This UDF defines the probe position as a function of time. This is a System UDF.
- Displacement Z UDF
m | This UDF defines the probe position as a function of time. This is a System UDF.
Download Sample File:
Probe Displacement
Display Attributes¶
- Visible
Enable or disable the visibility of this component.
- Hidden
Plane is active, but not shown in the GUI. This can be used when the setup is complicated or visually “busy”.
- Shown
Plane is active and visible.
- Mode
Defines if the visualization is a shaded rectangle or a wireframe rectangle.
Shaded
Wire
- Color
Select color for the shaded surface or wireframe.
- Width or Opacity
Defines the size of the wireframe or the opacity of the shading.
Static Probe Toolbar¶
Context-Specific Toolbar Forms |
Description |
|---|---|
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The Move form enables three-dimensional rigid body transform of object through free drag or point-to-point snapping. |
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The Rotate form enables three-dimensional rotation of geometry. |
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The Help command launches the M-Star reference documentation in your web browser. |
Move
Rotate
HelpFor a full description of each selection on the Context-Specific Toolbar, see Toolbar Selections.